A variety of catamenial devices has been used to collect vaginal discharges such as menstrual fluid. One such device is a sanitary napkin that is configured to be externally worn in the perineal region. An alternative to the sanitary napkin is a tampon which fits internally within the vaginal cavity to interrupt the external flow of menstrual blood. Hybrid devices that merge the structural features of sanitary napkins and tampons have also been proposed, as shown in U.S. Pat. Nos. 2,092,346 and 3,905,372.
An interlabial pad is a more recent catamenial device that provides greater convenience because of its small size. Examples of interlabial pads are shown in U.S. Pat. Nos. 3,983,873 and 4,175,561 that issued to A-Fem Medical Corporation (now known as QUANTRX® Biomedical Corporation) of Portland, Oreg. The interlabial pad has grown in popularity in recent years, as evidenced by many other patents that have issued on these pads, such as U.S. Pat. Nos. 6,270,486; 6,409,713; 6,409,714; 6,416,501; 7,033,342; and 7,074,214.
Another advantageous use of interlabial pads has been in the local or systemic administration of therapeutic agents. As disclosed in U.S. Pat. No. 6,811,549, it has been found that the interlabial pads provide targeted delivery of drugs for local and transdermal administration. The permeability of the labial area to many drugs (such as hormones, for example estrogen) has made the pads ideal drug delivery devices even for systemic disorders. However they are also advantageous in the targeted treatment of labial and peri-labial infection inflammation or in the retention of intravaginally delivered drugs.
Interlabial pads can also function as diagnostic collection devices. For example, U.S. Pat. No. 6,174,293 disclosed that interlabial pads could be applied externally to collect vaginal fluid and vaginal cells for subsequent diagnostic analysis. This collection technique was noted to be useful in the laboratory evaluation of tumors (such as vaginal cancer), infectious disorders (such as sexually transmitted diseases), hormone levels, and the detection of drugs of abuse.
Absorbent pads have also been used in the treatment of urinary incontinence, for example by collecting small amounts of liquid discharged by a subject who has stress incontinence. More recently the use of self-retained pads has been provided for the treatment of anal conditions, such as hemorrhoids, or for absorbing anal leakage, as in published U.S. Patent Publication 2005/182376.
Although the use of interlabial pads represents a significant advance in the field, existing interlabial pads have sometimes interfered with diagnostic assays. The materials some pads are made of can disrupt cellular structures that are collected for pathological examination (for example in a Pap smear). Some collection pads are also susceptible to bacterial overgrowth during storage and shipment, or contain materials that bind cells and other biological materials of diagnostic interest.
Another problem with some prior pads is that they have a low density core that wicks fluid to the center of the pad such that the fluid distributes itself preferentially in the absorbent material long the length of the pad. This distribution tends to cause the pad to leak from its ends.
One object of certain embodiments of the current disclosure is to provide a perineal pad that, in addition to serving as a catemenial, urine collection or drug delivery device, is also useful in the collection of liquids (such as vaginal or anal liquids) for diagnostic analysis.
The disclosed device is also suitable for the perineal (for example interlabial or anal) administration of therapeutic substances for direct topical or transdermal delivery.